How will the following be affecte on cutting a converging lens into two equal halves along the principal axis?
focal length?

Prove that for spherical mirrors ,the product of the distances of the object and the image from the principal focus is always equal to the square of the principal focal length.

If the focal length of a converging lens is 50 cm. What is the power of the Lens ?

What is the focal lengthof the combination of a convex lens of focal length 30 cm in contact with a concave lens of focal length 20 cm ? Is the system a converging or diverging lens ? Ignore thickness of the lenses.

What happens if abar magnet is cut into two equal pieces:along its length.

Answer the following questions: Magnifying power of a simple microscope is inversely proportional to the focal length of the lens. What then stops us from using a convex lens of smaller and smaller focal length and achieving greater and greater magnifying power?